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/*! \file
    \brief Defines common types used for all GEMM-like operators.
*/
#pragma once

#include "cutlass/cutlass.h"
#include "cutlass/coord.h"

namespace cutlass {
namespace gemm {

/////////////////////////////////////////////////////////////////////////////////////////////////

/// GEMM operand enumeration: D = A * B + C
enum class Operand {
    kA,  /// A multiplicand
    kB,  /// B multiplicand
    kC,  /// Source accumulator
    kD   /// Destination accumulator
};

/////////////////////////////////////////////////////////////////////////////////////////////////

/// Shape of a matrix multiply-add operation
template <
        /// Rows of matrix product
        int M = 1,
        /// Columns of matrix product
        int N = 1,
        /// Inner dimension of matrix product
        int K = 1>
struct GemmShape {
    static int const kM = M;
    static int const kN = N;
    static int const kK = K;

    static int const kMN = M * N;
    static int const kMK = M * K;
    static int const kKN = N * K;
    static int const kMNK = M * N * K;

    static int const kCount = kMNK;

    //
    // Static member functions
    //

    /// Returns a Coord object
    CUTLASS_HOST_DEVICE
    static Coord<3> toCoord() { return make_Coord(kM, kN, kK); }
};

/////////////////////////////////////////////////////////////////////////////////////////////////

/// Type alias of the transpose of a GemmShape
template <
        /// concept: GemmShape
        typename Shape>
using GemmShapeTranspose = GemmShape<Shape::kN, Shape::kM, Shape::kK>;

////////////////////////////////////////////////////////////////////////////////////////////////////

/// GemmCoord is a structure derived from Coord<3> that specifies a location
/// within the coordinate space of a GEMM problem.
struct GemmCoord : public Coord<3, int> {
    /// Integer-valued index
    typedef int Index;

    /// Base type is a Coord of rank=3
    typedef Coord<3, Index> Base;

    /// GEMM M dimension - rows of the output C matrix
    static int const kM = 0;

    /// GEMM N dimension - columns of the output C matrix
    static int const kN = 1;

    /// GEMM K dimension - inner dimension of the GEMM problem
    static int const kK = 2;

    //
    // Methods
    //

    /// Default ctor
    CUTLASS_HOST_DEVICE
    GemmCoord() {}

    /// Constructs from Coord<3> and a batch
    CUTLASS_HOST_DEVICE
    GemmCoord(Coord<3, Index> const& coord)
            : Base(make_Coord(coord[0], coord[1], coord[2])) {}

    /// Helper to construct from a K, N, M, batch variables
    CUTLASS_HOST_DEVICE
    GemmCoord(Index m, Index n, Index k) : Base(make_Coord(m, n, k)) {}

    /// Returns the GEMM M coordinate
    CUTLASS_HOST_DEVICE
    Index const& m() const { return this->at(kM); }

    /// Returns reference to the GEMM M coordinate
    CUTLASS_HOST_DEVICE
    Index& m() { return this->at(kM); }

    /// Returns the GEMM N coordinate
    CUTLASS_HOST_DEVICE
    Index const& n() const { return this->at(kN); }

    /// Returns reference to the GEMM N coordinate
    CUTLASS_HOST_DEVICE
    Index& n() { return this->at(kN); }

    /// Returns the GEMM K coordinate
    CUTLASS_HOST_DEVICE
    Index const& k() const { return this->at(kK); }

    /// Returns reference to the GEMM K coordinate
    CUTLASS_HOST_DEVICE
    Index& k() { return this->at(kK); }

    /// Obtains a Coord<3> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<3> mnk() const { return make_Coord(m(), n(), k()); }

    /// Obtains a Coord<3> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<3> knm() const { return make_Coord(k(), n(), m()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> nm() const { return make_Coord(n(), m()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> mn() const { return make_Coord(m(), n()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> mk() const { return make_Coord(m(), k()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> km() const { return make_Coord(k(), m()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> nk() const { return make_Coord(n(), k()); }

    /// Obtains a Coord<2> from GemmCoord
    CUTLASS_HOST_DEVICE
    Coord<2> kn() const { return make_Coord(k(), n()); }

    //
    // Coord operators
    //

    /// Element-wise addition
    CUTLASS_HOST_DEVICE
    GemmCoord operator+(Base const& b) const {
        return GemmCoord(Base::operator+(b));
    }

    /// Element-wise subtraction
    CUTLASS_HOST_DEVICE
    GemmCoord operator-(Base const& b) const {
        return GemmCoord(Base::operator-(b));
    }

    /// Element-wise multiplication
    CUTLASS_HOST_DEVICE
    GemmCoord operator*(Base const& b) const {
        return GemmCoord(Base::operator*(b));
    }

    /// Element-wise division
    CUTLASS_HOST_DEVICE
    GemmCoord operator/(Base const& b) const {
        return GemmCoord(Base::operator/(b));
    }

    /// In-place addition
    CUTLASS_HOST_DEVICE
    GemmCoord& operator+=(Base const& b) {
        Base::operator+=(b);
        return *this;
    }

    /// In-place subtraction
    CUTLASS_HOST_DEVICE
    GemmCoord& operator-=(Base const& b) {
        Base::operator-=(b);
        return *this;
    }

    /// In-place multiplication
    CUTLASS_HOST_DEVICE
    GemmCoord& operator*=(Base const& b) {
        Base::operator*=(b);
        return *this;
    }

    /// In-place division
    CUTLASS_HOST_DEVICE
    GemmCoord& operator/=(Base const& b) {
        Base::operator/=(b);
        return *this;
    }
};

////////////////////////////////////////////////////////////////////////////////////////////////////

/// BatchedGemmCoord is a structure derived from Coord<4> that specifies a
/// location within the coordinate space of a batched GEMM problem.
struct BatchedGemmCoord : public Coord<4, int> {
    /// Integer-valued index
    typedef int Index;

    /// Base type is a Coord of rank=4
    typedef Coord<4, Index> Base;

    /// GEMM M dimension - rows of the output C matrix
    static int const kM = 0;

    /// GEMM N dimension - columns of the output C matrix
    static int const kN = 1;

    /// GEMM K dimension - inner dimension of the GEMM problem
    static int const kK = 2;

    /// GEMM Batch dimension - inner dimension of the GEMM problem
    static int const kBatch = 3;

    //
    // Methods
    //

    /// Default ctor
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord() {}

    /// Constructs from Coord<4>
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord(Base const& coord) : Base(coord) {}

    /// Helper to construct from a K, N, M, and batch variables
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord(Index m, Index n, Index k, Index b)
            : Base(make_Coord(m, n, k, b)) {}

    /// Returns the GEMM M coordinate
    CUTLASS_HOST_DEVICE
    Index const& m() const { return this->at(kM); }

    /// Returns reference to the GEMM M coordinate
    CUTLASS_HOST_DEVICE
    Index& m() { return this->at(kM); }

    /// Returns the GEMM N coordinate
    CUTLASS_HOST_DEVICE
    Index const& n() const { return this->at(kN); }

    /// Returns reference to the GEMM N coordinate
    CUTLASS_HOST_DEVICE
    Index& n() { return this->at(kN); }

    /// Returns the GEMM K coordinate
    CUTLASS_HOST_DEVICE
    Index const& k() const { return this->at(kK); }

    /// Returns reference to the GEMM K coordinate
    CUTLASS_HOST_DEVICE
    Index& k() { return this->at(kK); }

    /// Returns the GEMM batch coordinate
    CUTLASS_HOST_DEVICE
    Index const& batch() const { return this->at(kBatch); }

    /// Returns reference to the GEMM batch coordinate
    CUTLASS_HOST_DEVICE
    Index& batch() { return this->at(kBatch); }

    /// Obtains a GemmCoord from BatchedGemmCoord
    CUTLASS_HOST_DEVICE
    GemmCoord mnk() const { return GemmCoord(m(), n(), k()); }

    /// Obtains a Coord<4> from BatchedGemmCoord
    CUTLASS_HOST_DEVICE
    Coord<4> mnkb() const { return make_Coord(m(), n(), k(), batch()); }

    //
    // Coord operators
    //

    /// Element-wise addition
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord operator+(Base const& b) const {
        return BatchedGemmCoord(Base::operator+(b));
    }

    /// Element-wise subtraction
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord operator-(Base const& b) const {
        return BatchedGemmCoord(Base::operator-(b));
    }

    /// Element-wise multiplication
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord operator*(Base const& b) const {
        return BatchedGemmCoord(Base::operator*(b));
    }

    /// Element-wise division
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord operator/(Base const& b) const {
        return BatchedGemmCoord(Base::operator/(b));
    }

    /// In-place addition
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord& operator+=(Base const& b) {
        Base::operator+=(b);
        return *this;
    }

    /// In-place subtraction
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord& operator-=(Base const& b) {
        Base::operator-=(b);
        return *this;
    }

    /// In-place multiplication
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord& operator*=(Base const& b) {
        Base::operator*=(b);
        return *this;
    }

    /// In-place division
    CUTLASS_HOST_DEVICE
    BatchedGemmCoord& operator/=(Base const& b) {
        Base::operator/=(b);
        return *this;
    }
};

/////////////////////////////////////////////////////////////////////////////////////////////////

enum class GemmUniversalMode {
    kGemm,
    kGemmSplitKParallel,
    kBatched,
    kArray,
    kInvalid
};

////////////////////////////////////////////////////////////////////////////////////////////////////

}  // namespace gemm
}  // namespace cutlass
